Xin Zhang
2011-May-12 07:58 UTC
[R] How to extract information from the following dataset?
Hi all, I have never worked with this kind of data before, so Please help me out with it. I have the following data set, in a csv file, looks like the following: Jan 27, 2010 16:01:24,000 125 - - - Jan 27, 2010 16:06:24,000 125 - - - Jan 27, 2010 16:11:24,000 176 - - - Jan 27, 2010 16:16:25,000 159 - - - Jan 27, 2010 16:21:25,000 142 - - - Jan 27, 2010 16:26:24,000 142 - - - Jan 27, 2010 16:31:24,000 125 - - - Jan 27, 2010 16:36:24,000 125 - - - Jan 27, 2010 16:41:24,000 125 - - - Jan 27, 2010 16:46:24,000 125 - - - Jan 27, 2010 16:51:24,000 125 - - - Jan 27, 2010 16:56:24,000 125 - - - Jan 27, 2010 17:01:24,000 157 - - - Jan 27, 2010 17:06:24,000 172 - - - Jan 27, 2010 17:11:25,000 142 - - - Jan 27, 2010 17:16:24,000 125 - - - Jan 27, 2010 17:21:24,000 125 - - - Jan 27, 2010 17:26:24,000 125 - - - Jan 27, 2010 17:31:24,000 125 - - - Jan 27, 2010 17:36:24,000 125 - - - Jan 27, 2010 17:41:24,000 125 - - - Jan 27, 2010 17:46:24,000 125 - - - Jan 27, 2010 17:51:24,000 125 - - - ...... The first few columns are month, day, year, time with OS3 accuracy. And the last number is the measurement I need to extract. I wonder if there is a easy way to just take out the measurements only from a specific day and hour, i.e. if I want measurements from Jan 27 2010 16:--:-- then I get 125,125,176,159,142,142,125,125,125,125,125,125. Many thanks!! -- Xin Zhang Ph.D Candidate Department of Statistics University of California, Riverside [[alternative HTML version deleted]]
Jose-Marcio Martins da Cruz
2011-May-12 08:43 UTC
[R] How to extract information from the following dataset?
Xin Zhang wrote:> Hi all, > > I have never worked with this kind of data before, so Please help me out > with it. > I have the following data set, in a csv file, looks like the following: > > Jan 27, 2010 16:01:24,000 125 - - - > Jan 27, 2010 16:06:24,000 125 - - - > Jan 27, 2010 16:11:24,000 176 - - - > Jan 27, 2010 16:16:25,000 159 - - - > Jan 27, 2010 16:21:25,000 142 - - - > Jan 27, 2010 16:26:24,000 142 - - - > Jan 27, 2010 16:31:24,000 125 - - - > Jan 27, 2010 16:36:24,000 125 - - - > Jan 27, 2010 16:41:24,000 125 - - - > Jan 27, 2010 16:46:24,000 125 - - - > Jan 27, 2010 16:51:24,000 125 - - - > Jan 27, 2010 16:56:24,000 125 - - - > Jan 27, 2010 17:01:24,000 157 - - - > Jan 27, 2010 17:06:24,000 172 - - - > Jan 27, 2010 17:11:25,000 142 - - - > Jan 27, 2010 17:16:24,000 125 - - - > Jan 27, 2010 17:21:24,000 125 - - - > Jan 27, 2010 17:26:24,000 125 - - - > Jan 27, 2010 17:31:24,000 125 - - - > Jan 27, 2010 17:36:24,000 125 - - - > Jan 27, 2010 17:41:24,000 125 - - - > Jan 27, 2010 17:46:24,000 125 - - - > Jan 27, 2010 17:51:24,000 125 - - - > ...... > > The first few columns are month, day, year, time with OS3 accuracy. And the > last number is the measurement I need to extract. > I wonder if there is a easy way to just take out the measurements only from > a specific day and hour, i.e. if I want measurements from Jan 27 2010 > 16:--:-- > then I get 125,125,176,159,142,142,125,125,125,125,125,125. > Many thanks!!The easiest is in the shell, if you're using some flavour of unix : grep "Jan 27, 2010 16" filein.txt | awk '{print $5}' > fileout.txt and use fileout which will contain only the column of data you want.>--
I have the following data set, in a csv file, looks like the following: Jan 27, 2010 16:01:24,000 125 - - - Jan 27, 2010 16:06:24,000 125 - - - ...... The first few columns are month, day, year, time with OS3 accuracy. And the last number is the measurement I need to extract. I wonder if there is a easy way to just take out the measurements only from a specific day and hour -- Xin Zhang Ph.D Candidate Department of Statistics University of California, Riverside ------------------------------------------------------------------- I use strptime to configure the date format in my times series dataset. First check to see how the dates are read. For example: # check the structure str(your_file) 'data.frame' ...etc This tells me that my original date is a factor but not in POSIXlt format. #check your column dates head(your_file) [1] "1984-01-26" "1984-02-09" "1984-03-01" "1984-03-15" "1984-03-29" "1984-04-12" These are discrete column dates. #convert your date format your_file$date<- strptime(your_file$date,"%m/%d/%Y") call ?strptime for options Example: For a specific day or hour, strptime would utilize: strptime(your_file$date,"%d/%I") for day and hour. Once you extract the type of date format you want, run str(your_file) again to confirm the format change. Does this answer your question? Best, ----- ------------------------------- Heather A. Wright, PhD candidate Ecology and Evolution of Plankton Stazione Zoologica Anton Dohrn Villa Comunale 80121 - Napoli, Italy -- View this message in context: http://r.789695.n4.nabble.com/How-to-extract-information-from-the-following-dataset-tp3516752p3516952.html Sent from the R help mailing list archive at Nabble.com.